Smoking, stages of change and decisional balance in Iceland and Sweden.

INTRODUCTION: Smoking remains a significant health problem. Smoking interventions are important but selection of successful quitters can be difficult. OBJECTIVE: To characterise smokers with emphasis on two constructs of the transtheoretical model, the stages of change and decisional balance. METHODS: A random sample from adults aged 40 and over in Reykjavik, Iceland, and Uppsala, Sweden. Smokers were defined as being in the stage of pre-contemplation (not thinking of quitting within the next 6 months), contemplation (thinking of quitting within the next 6 months) or preparation (thinking of quitting within the next 30 days, having managed to quit for at least 24 h within the last 12 months). RESULTS: A total of 226 participants were smokers: 72 (32%) were in the pre-contemplation stage, 126 (56%) in the contemplation stage and 28 (12%) in the preparation stage. A younger age, higher body mass index (BMI) and higher educational level were significantly related to being in a more advanced stage. A significant association was observed between decisional balance and stages of change such that decreased importance of the positive aspects of smoking and increased importance of the negative aspects of smoking were independently associated with an increased readiness to quit. CONCLUSION: The motivated smoker is likely to be young and educated with an above average BMI. A smoker in the contemplation stage is likely to maintain the negative aspects of smoking at a high level. Decreasing the value of the pros of smoking may facilitate the shift towards the stage of preparation.

A novel MALDI-TOF based methodology for genotyping single nucleotide polymorphisms.

A new MALDI-TOF based detection assay was developed for analysis of single nucleotide polymorphisms (SNPs). It is a significant modification on the classic three-step minisequencing method, which includes a polymerase chain reaction (PCR), removal of excess nucleotides and primers, followed by primer extension in the presence of dideoxynucleotides using modified thermostable DNA polymerase. The key feature of this novel assay is reliance upon deoxynucleotide mixes, lacking one of the nucleotides at the polymorphic position. During primer extension in the presence of depleted nucleotide mixes, standard thermostable DNA polymerases dissociate from the template at positions requiring a depleted nucleotide; this principal was harnessed to create a genotyping assay. The assay design requires a primer- extension primer having its 3'-end one nucleotide upstream from the interrogated site. The assay further utilizes the same DNA polymerase in both PCR and the primer extension step. This not only simplifies the assay but also greatly reduces the cost per genotype compared to minisequencing methodology. We demonstrate accurate genotyping using this methodology for two SNPs run in both singleplex and duplex reactions. We term this assay nucleotide depletion genotyping (NUDGE). Nucleotide depletion genotyping could be extended to other genotyping assays based on primer extension such as detection by gel or capillary electrophoresis.